This invention relates to a filter assembly having a filter element provided by a pleated media. Structural support for the pleated media is provided by an adhesive.
Filter assemblies such as oil filters typically employ a filter element constructed of a pleated media such as paper. The pleated media is arranged in a cylindrical shape. A steel center tube is typically arranged in a central bore defined by the pleated media to provide structural support to the pleated media so that the pleated media does not collapse under fluid pressure. There has been an effort in the filter industry to eliminate as many steel components as possible.
Pleated media is also used in air filter applications. Typically the pleated media is provided in a flat rectangular shape. A perimeter of the pleated media includes a gasket for sealing against a filter housing. A steel screen is typically used on an outlet side of the pleated media to prevent the media from collapsing under the force generated by an air flow through the pleated media. Adhesive beads have been arranged along the pleated media on an inlet side opposite the steel screen to maintain a desired spacing between pleats. An adhesive such as hot melt glue has been used to provide the beads, which bridge the pleats.
It is desirable to eliminate the steel center tube from the filter assembly in, for example, an oil filter.